1. Field of the Invention
The present invention relates to improvement in portable lifting and hoisting devices. More particularly, the present invention relates to a portable hoist which is especially useful for moving and installing heavy objects in a small area.
Many domestic appliances, such as water heaters, air-conditioners, and the like, are installed on shelves or brackets above the floor level, and in the case of some air-conditioners, in windows or other wall openings which are well above the floor level. Often they are too heavy for one man to lift them into place and other than that requirement, one man can perform all of the installation work.
Some warehouses and storage rooms are so equipped as to prevent the utilization of any large power equipment for lifting heavy objects to a stacked position. Also, in areas away from a power source, such as in yards or during delivery by trucks, an occasional heavy and bulky item is required to be lifted and/or moved. With these considerations in mind, the present invention can be utilized however, utilization in other operations or uses can be noted.
2. Description of the Prior Art
Portable lifting or hoisting devices of the derrick or crane type, and consisting of a certain peculiar frame having folding base extensions a pivotally-attached spar or boom, and pushing members or handles, and equipped with hoisting mechanisms are well known. One such device can be found in U.S. Pat. No. 1,284,277 of Ewig et al. The device of this patent contains a worm gear operated winding mechanism which affords all the power necessary for lifting small appliances. There is further provided a large base frame over which the boom moves so as to provide the necessary stability.
U.S. Pat. No. 3,181,707 of Janssen relates to a hoisting apparatus for use in installing and removing heavy domestic appliances which is provided with a swinging crane arm for moving the load.
U.S. Pat. No. 45,865 of Rogers relates to a hoist which is intended to be attached to a hay wagon and used for lifting a load onto the wagon.